1. Field of the Invention
This invention relates to surgical procedures, such as laparoscopy, and, more particularly, to a jig for consistently guiding introduction of laparoscopic surgical instruments through a tissue in any of a number of preselected orientations.
2. Background Art
Laparoscopic surgery is a widely accepted alternative to conventional surgery. A principal advantage of laparoscopic surgery is that it generally requires only small incisions in the body tissue, thereby permitting the performance of many major surgical operations on an out-patient basis.
The inventor herein has obtained numerous U.S. patents covering instruments particularly adaptable for use in laparoscopic surgery. Among these are U.S. Pat. No. 4,935,006, entitled "Suction and Irrigation Device" and U.S. Pat. No. 4,944,741, entitled "Laparoscopic Instrument With Pivotable Support Arm".
It should be understood that laparoscopy, as used throughout this specification, is intended in a generic sense to include other surgical procedures, such as endoscopy, etc. which, from a mechanical standpoint, are performed in a similar manner.
The basic laparoscopic instrument consists of an elongate, hollow sleeve with proximal and distal ends, the latter of which is directed through body tissue and into a cavity in which the surgical procedure is to be performed. To facilitate insertion, a spike/trocar is directed through the sleeve and, when fully inserted therein, has a protruding, sharpened point at the distal sleeve end. After a small incision is made in the tissue, the sleeve, with the spike/trocar directed fully thereinto, is forced through the incision.
The inventor herein has devised structure for holding the sleeve in a relatively stable position with respect to tissue through which it extends to thereby facilitate instrument removal and introduction without disturbing the alignment of the sleeve. One such structure is shown in U.S. patent application Ser. No. 334,452, entitled "Laparoscopic Cannula". That device has a sleeve and a membrane thereon which is expandable once the distal end is projected into the body cavity and a slidable collar on the sleeve which, in conjunction with the membrane, positively captures the tissue wall. The collar has a tapered surface which depresses the tissue around the sleeve to provide a relatively airtight seal around the incision. This seal is required to maintain in the cavity CO.sub.2 gas or other gas that may be utilized to distend the cavity to facilitate performance of the surgical procedure. The tapered surface on the collar permits the angle of the sleeve axis to be changed with respect to the tissue without compromising the seal.
One problem with the above described device is that, while the sleeve is positively held in place on the tissue and the integrity of the seal maintained throughout a range of movement of the sleeve, that structure does not permit the sleeve to be selectively reoriented and maintained in the reoriented state. For example, if the sleeve is introduced at one location through the abdominal wall, the curvature of the abdominal wall, when distended, will naturally hold the sleeve in a first orientation. While the sleeve may be manually reoriented by the surgeon, the sleeve naturally tends back towards a centered position. It is difficult, if not impossible, for the surgeon to access a different area in the body cavity, and maintain that position of the sleeve, as to insert different instruments. As a result, it may instead be necessary to provide a separate incision, which is obviously undesirable if the second site is accessible through the first incision.
A further problem with the above system is that, regardless of how securely the sleeve is held relative to the tissue wall, the sleeve tends to float freely around the incision site due to the fact that the tissue wall itself is flexible. Upon the introduction of the instrument, the surgeon may be required to search each time for the exact location at which the operation is being performed.